Figure 4From: In vitro prion protein conversion suggests risk of bighorn sheep (Ovis canadensis) to transmissible spongiform encephalopathiesConversion efficiency ratio (CER) assay using laboratory mouse substrate. (A) Mouse CER assay substrate prepared at either pH 7.4 or 3.5 was incubated with RML mouse-adapted scrapie, domestic sheep classical scrapie, white-tailed deer (WTD) chronic wasting disease agent (CWD) or 263K strain of hamster-adapted scrapie. Control samples (labeled “none”) contained only an equal amount of infectious agent and no mouse substrate. Samples were analyzed for the presence of proteinase K-resistant prion protein by immunoblot with monoclonal antibody SAF 83. Raw densitometric values for each sample are displayed below each lane. (B) Bar graph indicating the average ratios (+/− standard deviation) between pH 7.4 and 3.5 mouse substrates for each infectious agent based on at least three independent assay runs. Lower-case letters refer to statistically homogeneous subsets (analysis of variance with Tukey-Kramer minimum significance differences method; p < 0.05).Back to article page